Box-shadow Dough

HTML-CSS
#1

Can some one explain, how the below Thumbnail ID element of box-shadow property’s works, i think it is RBGA, but what is meaning of 0 10px 20px, can any one explain what the use of 0 10px 20px in this code

#thumbnail {

box-shadow: 0 10px 20px rgba(0,0,0,0.19), 0 6px 6px rgba(0,0,0,0.23);

Your code so far


<style>
h4 {
  text-align: center;
  background-color: rgba(45, 45, 45, 0.1);
  padding: 10px;
  font-size: 27px;
}
p {
  text-align: justify;
}
.links {
  text-align: left;
  color: black;

}
#thumbnail {
  box-shadow: 0 10px 20px rgba(0,0,0,0.19), 0 6px 6px rgba(0,0,0,0.23);
}
.fullCard {
  width: 245px;
  border: 1px solid #ccc;
  border-radius: 5px;
  margin: 10px 5px;
  padding: 4px;
}
.cardContent {
  padding: 10px;
}
.cardText {
  margin-bottom: 30px;
}
</style>
<div class="fullCard" id="thumbnail">
<div class="cardContent">
  <div class="cardText">
    <h4>Alphabet</h4>
    <hr>
    <p><em>Google was founded by Larry Page and Sergey Brin while they were <u>Ph.D. students</u> at <strong>Stanford University</strong>.</em></p>
  </div>
  <div class="cardLinks">
    <a href="https://en.wikipedia.org/wiki/Larry_Page" target="_blank" class="links">Larry Page</a><br><br>
    <a href="https://en.wikipedia.org/wiki/Sergey_Brin" target="_blank" class="links">Sergey Brin</a>
  </div>
</div>
</div>

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 6.1; rv:75.0) Gecko/20100101 Firefox/75.0.

Challenge: Decrease the Opacity of an Element

Link to the challenge:

#2

Horizontal Length, Vertical Length, Blur Radius, rgba

#3

Google CSS box shadows and you’ll see, as with most css related googles W3 school website pops up. Use that now and for future reference. Its quicker than coming here.

#4

Box Shadow is described in detail later in the curriculum: https://www.freecodecamp.org/learn/responsive-web-design/applied-visual-design/add-a-box-shadow-to-a-card-like-element

#5